Art of coking hydrocarbons



May s, 1934.,

W. H. BEARDSLEY ART OF COKING HYDROCARBONS Filed May` ll 1931 Fig-.l

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INVENTOR ATTORNEYS Patented May 8, 1,934

UNITED STATES PATENT oFFlcE-f ART F COKING HYDROCARBONS a corporation ofMaine Application May 1, 1931, Serial No. 534,245

1 Claim.

This invention relates to improvements in the operation of systems forcarrying out the combined vapor phase cracking of oils, such as gas yoil or kerosene stocks, for the production of low- 5 er boiling oils,such as gasoline, and the coking of heavy oils, such as crudes, toppedcrudes, flux oils, and other residual stocks and the like, by passingthe hot vapor mixture from a vapor phase cracking operation, while stillat high tempera- 0 ture, in intimate contact with a liquid oil mixtureto be reduced to coke in a receptacle adapted to receive an accumulatingcharge of coke thereby comng this liquid oil mixture by the heat of thehot vapor mixture from the vapor phase l5 cracking operation.

The operation described in an application led February i9, 1929, SerialNumber 341,214, by Harry L. Pelzer, is an example of such operations.

The vapor mixtures from vapor phase cracking operations are peculiarlydifficult to handle prior to the separation of the tarry constituentswhich they normally contain as discharged, at temperatures upwards or"950 F., from the vapor phase cracking operation proper.Characteristically these tarry constituents of such vapor mixtures tendto form deposits choking or plugging any stagnant spaces in lines orvalves. The usual 'i' connection to two gate valves to connect one lineto either of two other lines, for example,

3@ even where the legs of the T are very short and are connecteddirectly to the gate valves, is not satisfactory for this purposebecause, with the vapor mixture passing through either of the alternatepassages, a deposit tends to form in the stagnant leg of the T renderingthe operation of the valve system uncertain and irregular.

Two-way valves embodying plug-type closure members assist in theelimination of stagnant regions but in such service such valves tend to49 freeze in one position or to become locked in 'one position due tothe development of bridges. or' hard coke between the closure member andthe valve body. lThis invention relates particularly to improvementsminimizing such diiiiculties when such valves are embodied in systemsfor carrying out such operations.

A two-way valve adapted for the practice of the invention is illustratedin Figs. 1 and 2 ofthe accompanying drawing, Fig. 1 being a section 50through the axis of the closure member of the valve and Fig. 2 being asection on line 2--2 of Fig. 1, a system embodying the valvesillustrated in detail in Figs. 1 and 2 being illustrated, dia- Agrammatically and conventionally, in Fig. 3. Referring to Fig. 3 of thedrawing, the system illustrated may be operated as described inapplication Serial Number 341,214 previously mentioned, the connections16 and 7 and the receptacles A, B, C and D corresponding to theconnections and receptacles so designated in that ap- 60 plication.- Thetwo-way valves in this system are shown in position to permit flow fromthe heater through connection 16 through receptacles B and C insuccession to connection '7. To establish ow through receptacles C and Din succession, for example, two-way valves 20 and 21 are rst reversedand two-way valves 22 and 23 are then reversed. A similar operationestablishes flow through receptacles D and A in succession, throughreceptacles A and B in succession, and so on.

These two-way valves, illustrated in detail in Figs. l and 2, comprise afrustro-conical rotatable plug 4 seated in a body 5. The body 5 isprovided With three ports 6, 7 and 8, and the plug 4 75 is provided withtwo communicating ports 9 and 10 arranged so that by rotation of theplug port 8 can be connected either to port 6 or to port 7. Chambers 11and 12 are provided in the body 5 at opposite ends of the plug 4, avalved connection 13 80 communicating with chamber l1 and a valveconnection lll with chamber 12. In addition to the passage connectingthe ports 9 and 10 through the plug 4, passages 15 and 17 are providedthrough the plug 4, these passages communicating with the chambers 11and 12 through apertures in the opposite ends of the plug.

The `operation of the invention in the system illustrated in Fig. 3 willbe illustrated by a specific reference to the valve 22. Assume a mixtureof oil vapors at a temperature of l000-1020 F., for example, flowingfrom the heater through connections 16 and 24, through the valve 22 andthrough connections 25 and 27 to the coking receptacle B, the valvedconnections 13 and 14 be- 95 ing closed. To reverse the position of thevalve 22 so that the vapor mixture will pass through connection 28instead of connection 26, a cooling iiuid such as steam or a mixture ofhydrocarbon gases high in methane at a temperature lower than thatprevailing in the valve by a margin of 30D-400 F. or more is suppliedthrough connection 13, passed through the passages l5 and 17 in thevalve plug 4 and discharged through connection 14. The passage of thiscooling uid through the passages in the valve plug is initiated justbefore it is desired to reverse the valve. This sudden cooling of thevalve plug without corresponding cooling of the surrounding portions ofthe valve body frees the valve plug from its seat in the valve body andit is then rotated to the desired position, valved connections 13 and 14closed as soon asthe valve plug is sumciently free from its seat in thevalve body Any cooling iluid stable and inert ywith respet to the partso! the valve with which it contacts at the temperatures prevailing inthe valve and of sufiiciently high specific heat may be used in carryingout the invention. Steam and hydrocarbon gas mixtures high in methaneare particularly useful in carrying out the invention.

I claim:

In the operation ot systems comprising a heater in which oil is heatedto a cracking temperature upwards of 950 F., a coking receptacle inwhich heavy oil is Vreduced to coke by the heat of the hot oil productsdischarged from'said heater and a connection for discharging said hotoil products from said heater into said coking receptacle including avalve comprising a frustro-conical rotatable plug 'seated in a bodyprovided with ports Vcommunicating with said connection, the im- WILSONHULL BEARDSLEY.

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